Zend_Db ignore default charset of Mysql

While I set my Mysql database default character set as UTF-8, Zend_Db_Adapter does not pick up the setting. Zend_Db write to Mysql using its own default character set (I guess it’s ISO-8859-1), unless it is specifically told by

$dbAdapter->query(“SET NAMES ‘utf8′”);

before

Zend_Db_Table::setDefaultAdapter($dbAdapter);